Film layer structure, display substrate, and display device

ABSTRACT

The utility model discloses a film layer structure, an array substrate and a display device, relating to the technical field of display, in order to improve the bending resistance of the film layer structure, thereby reducing the possibility of cracking or even breaking of the film layer structure during the stress process of the display device. The film layer structure comprises a film layer substrate, and the edge of the film layer substrate is provided with a curved edge for adjusting the stress distribution of the film layer structure. The array substrate comprises the film layer structure proposed by the technical scheme. The film layer structure, array substrate and display device provided by the utility model are used in display.

TECHNICAL FIELD

The utility model relates to the technical field of display, in particular to a film layer structure, an array substrate and a display device.

BACKGROUND

Flexible display device is a flexible low-power display device, which is often applied to mobile terminals such as wearable display devices.

The existing flexible display device is a multi-layer film structure, and partial prestress exists between each layer film structure to a greater or lesser extent, so that in the bending process of the flexible display device, the strength of some film layer structures may be relatively small, resulting in relatively small bending resistance of the film layer structures, cracking and even fracture problems.

SUMMARY

The utility model aims to provide a film layer structure, an array substrate and a display device, so as to improve the bending resistance of the film layer structure, thereby reducing the possibility of cracking or even breaking of the film layer structure in the stress process of the display device.

In order to achieve the above purpose, the utility model provides the following technical scheme:

The invention relates to a film layer structure, which comprises a film layer substrate, wherein the edge of the film layer substrate is provided with a curved edge for adjusting the stress distribution of the film layer structure.

Compared with the prior art, in the film layer structure provided by the utility model, the edge of the film layer substrate is provided with a curved edge for adjusting the stress distribution of the film layer structure. At this time, when the finite element simulation technology is used to simulate the film layer structure, one end of the film layer substrate is fixed and the other end of the film layer substrate is loaded with displacement load. The simulation results prove that when the edge of the film layer substrate has a curved edge, the stress distribution of the film layer structure can be adjusted to make the stress distribution of the film layer structure uniform. Therefore, when the edge of the film layer substrate included in the film layer structure provided by the utility model has a curved edge, the problem of stress concentration in the film layer structure can be effectively relieved, so that when the film layer structure is applied to flexible objects such as flexible display devices, the problem of cracks or even fractures in the film layer structure due to stress states such as stretching or bending of the flexible objects can be reduced.

The utility model also provides an array substrate, which comprises at least one film layer structure described in the above technical scheme.

Compared with the prior art, the beneficial effects of the array substrate provided by the utility model are the same as those of the film layer structure described in the above-mentioned technical scheme, and will not be repeated here.

The utility model also provides a display device, which comprises the array substrate described in the above technical scheme.

Compared with the prior art, the beneficial effects of the display device provided by the utility model are the same as those of the array substrate described in the above-mentioned technical scheme, and will not be repeated here.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the utility model and form a part of the utility model. The illustrative embodiment of the utility model and its description are used to explain the utility model and do not constitute improper limitation of the utility model. In the drawings:

FIG. 1 is a schematic diagram of a film layer structure provided by an embodiment of the utility model;

FIG. 2 is a schematic diagram of the finite element optimization result of the film layer structure provided by the embodiment of the utility model.

FIG. 3 is a finite element simulation diagram of a film layer structure provided by an embodiment of the utility model.

REFERENCE NUMERAL

1- film layer substrate, 10- curved edge unit; 100- stress adjustment hole, 101- first stress adjustment hole; 102- second stress adjustment hole, 11- curve edge; 111a- first large curvature arc 111b- first small curvature arc edge, edge; 112a- second large curvature arc 112b- second small curvature arc edge, edge.

DETAILED DESCRIPTION

In the following, the technical scheme in the embodiment of the utility model will be described clearly and completely with reference to the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative labor are within the scope of protection of the utility model.

In the prior art, the thickness of the flexible display device is much smaller than the length and width of the flexible display device, so that the flexible display device is in a plane stress structure. However, since the flexible display device is a multi-layer film structure, there is a certain load transfer between the various film layer structures included in the flexible display device with planar stress structure, which will affect some film layer structures with relatively small strength and lead to problems in the flexible display device. These effects are manifested by warping, peeling, cracking and other problems of the film layer structure included in the flexible display device, and even delamination or detachment of the film layer structure from the substrate.

At present, high-power microscopes are generally used to observe the changes of materials of various film layers included in flexible display devices. However, this method cannot directly reflect the stress distribution of the film layer structure included in the display device.

in view of this, the inventor proposes to use the finite element simulation method to simulate the film layer structure included in the existing flexible display device. For example, the finite element simulation method is adopted to simulate the metal wires of the existing source-drain film layer. In the simulation, one end of the metal wire is fixed and the other end of the metal wire is loaded with displacement load. The simulation results show that the maximum tensile stress of the wire is 321.5 MPa, and stress concentration occurs at the fixed end of the wire. At this time, the fixed end of the metal wire is also the most easily broken place. This is because the end of the wire is loaded with displacement load, which causes the wire to deform to some extent. In the process of metal wire deformation, the metal wire is accompanied by corresponding stress. At the place where the stress of the metal wire is the largest, the strain of the structure of the metal wire is also the largest. When the strain at the maximum stress of the metal wire exceeds the allowable strain or the stress exceeds the allowable stress, the structure will be destroyed and the whole screen will be damaged.

From the above, it can be seen that the stress distribution of the metal lines of the above-mentioned source-drain film layer is uneven, and the metal lines of the source-drain film layer are easy to fracture due to the relatively thin and brittle metal lines of the source-drain film layer. To solve this problem, as shown in FIG. 1, the embodiment of the utility model provides a film layer structure, which can be a film layer structure with greater brittleness, such as a metal film layer structure made of common metal materials, or a film layer structure made of inorganic materials similar to the elastic modulus of the film layer structure of metal materials. The film layer structure includes a film layer substrate 1. The edge of the film layer substrate 1 has a curved edge 11 for adjusting the stress distribution of the film layer structure. The curved edge 11 may be a common arc shape or a wave-breaking shape, which is not limited here.

The inventors used finite element simulation method to simulate the above film layer structure. In the process of simulation, one end of the film layer structure is fixed and the other end is loaded. The simulation results prove that when the edge of the film layer substrate 1 has a curved edge 11, the stress distribution of the film layer structure can be adjusted to make the stress distribution of the film layer structure uniform. Therefore, when the edge of the film layer substrate 1 included in the film layer structure provided by the embodiment of the utility model has a curved edge 11, the problem of stress concentration in the film layer structure can be effectively relieved, and when the film layer structure is applied to flexible objects such as flexible display devices, the problem of cracks or even fractures of the film layer structure caused by bending of the flexible objects can be reduced.

Moreover, the finite element simulation method is adopted to simulate the film layer structure, which can not only carry out numerical simulation according to the design requirements to simulate various test schemes, reduce the test time and funds, and shorten the cycle period of design and analysis, but also adopt optimal design to reduce material consumption or cost loss. Not only that, when the finite element simulation method is used to simulate the film layer structure, various test schemes are simulated to reduce the test time and cost.

In addition, the potential problems found in advance before the flexible screen is manufactured are used to simulate the possible problems in the bending process of the flexible screen according to different boundary conditions, and the deformation problem of the flexible screen is improved and solved through different structural designs.

In some embodiments, as shown in FIG. 1, the film layer substrate 1 has a plurality of stress adjustment holes 100 for adjusting the stress distribution of the film layer structure. The stress adjustment holes 100 may be round holes, oval holes or irregular holes, and the aperture sizes of the plurality of stress adjustment holes 100 may be the same or different. When the film layer structure provided in this embodiment is deformed, stretched or bent, when the plurality of stress adjustment holes 100 are formed in the film layer substrate 1 included in the film layer structure, the stress adjustment holes 100 are deformed along the direction of the generated force under the action of the force generated by deformation, stretching or bending. For example, when the film layer structure is a rectangular film layer structure and the plurality of stress adjustment holes 100 formed in the film layer substrate 1 included in the film layer structure are circular stress adjustment holes, if the film layer structure is deformed, stretched or bent along the length direction, the circular stress adjustment holes will extend along the length direction of the film layer structure, changing from the original circular stress adjustment holes to oval stress adjustment holes. In the process that the circular stress adjustment hole becomes an oval stress adjustment hole, it is also a process that the structural stress of the film layer is uniformly distributed in the middle of the film layer.

When the film layer structure provided by the embodiment of the utility model and the existing film layer structure stretch or bend to the same degree, the internal stress generated by the film layer structure provided by the embodiment of the utility model is smaller than the internal stress generated by the existing film layer structure, therefore, compared with the prior art, the film layer structure provided by the embodiment of the utility model has better strength and flexibility, and can be applied to flexible objects such as flexible display devices.

It should be noted that the plurality of stress adjustment holes 100 can be distributed on the film layer substrate 1 in the following manner:

In the first mode, a plurality of stress adjustment holes 100 are uniformly distributed on the film layer substrate 1.

In the second mode, a plurality of stress adjustment holes 100 are unevenly distributed on the film layer substrate 1.

In the third mode, the density of the stress adjustment holes 100 provided in the film layer substrate 1 gradually decreases along the direction from the center to the edge of the film layer substrate 1. In this case, the finite element simulation experiment proves that it is beneficial to make the stress distribution in the middle of the film layer substrate 1 uniform.

The fourth way is that the spacing between the two adjacent stress adjustment holes 100 is larger than the diameter of at least one of the two adjacent stress adjustment holes 100.

The finite element simulation method is used to simulate the film layer substrate 1 provided in this embodiment, and it is found that when the film layer substrate 1 has a plurality of stress adjustment holes 100 for adjusting the stress distribution of the film layer structure, the stress distribution uniformity of the film layer structure can be effectively improved, so that the stress flexibility of the film layer structure is better.

The specific implementation modes of the above-mentioned film layer structure are various, and will be described in detail below with reference to the attached drawings.

As shown in FIG. 1 and FIG. 2, the film layer substrate 1 includes at least one curved edge unit 10, and the plurality of stress adjustment holes 100 include at least one first stress adjustment hole 101 corresponding to the at least one curved edge unit 10 and at least one second stress adjustment hole 102 corresponding to the at least one curved edge unit 10. Each curved edge unit 10 includes a first arc edge subunit and a second arc edge subunit connected together. The first arc side subunit has a first stress adjustment hole 101 for adjusting the stress distribution of the film layer structure, and the second arc side subunit has a second stress adjustment hole 102 for adjusting the stress distribution of the film layer structure.

As shown in FIG. 1 and FIG. 2, each curved edge unit 10 includes a first curved edge subunit having at least a first large curvature curved edge 111 a and a first small curvature curved edge 111 b, each curved edge unit 10 includes a second curved edge subunit having at least a second large curvature curved edge 112 a and a second small curvature curved edge 112 b; the first large curvature arc 111 a included in the first arc sub-unit in each curved edge unit 10 is connected to the second small curvature arc 112 b included in the second arc sub-unit, and the first small curvature arc 111 b included in the first arc sub-unit in each curved edge unit 10 is connected to the second large curvature arc 112 a included in the second arc sub-unit.

Specifically, as shown in FIG. 1 and FIG. 2, the first large curvature arc 111 a included in the first arc sub-unit in one of the two adjacent curved edge units 10 is connected to the second small curvature arc 112 b included in the second arc sub-unit in the other curved edge unit 10. The first small curvature arc 111 b included in the first arc sub-unit in one curved edge unit 10 is connected with the second large curvature arc 112 a included in the second arc sub-unit in the other curved edge unit 10. In this case, the curved edges 11 of the film layer structure formed by the above-mentioned curved edge units 10 are arranged in an alternating pattern of small curvature curved edges and large curvature curved edges.

In some embodiments, as shown in FIG. 1 and FIG. 2, the curvatures of the first large curvature arc 111 a and the second large curvature arc 112 a are the same in each curved edge unit 10, the curvatures of the first small curvature arc 111 b and the second small curvature arc 112 b in each curved edge unit 10 are the same, and the arc radius of the first small curvature arc 111 b is larger than the diameter of the first stress adjustment hole 101.

Alternatively, as shown in FIG. 1 and FIG. 2, the ratio of the arc radius of the first large curvature arc 111 a to the arc radius of the first small curvature arc 111 b is (1.8-3.6):(4.5-6.5), and the ratio of the arc radius of the first small curvature arc 111 b to the diameter of the first stress adjustment hole 101 is (4.8-6.5):(2.5-4.5), the ratio of the shortest distance from the first large curvature arc 111 a to the geometric center of the first stress adjustment hole 101 to the diameter of the first stress adjustment hole 101 is (10-12):(2.5-4.5).

The finite element simulation method is used to simulate the film layer structure. The simulation results show that the maximum tensile stress of the film layer structure is 300.1 MPa to 312.8 MPa, which is less than the maximum tensile stress of the existing metal wire film layer structure. In addition, as can be seen from FIG. 3, the stress enough for the film layer junction provided by the embodiment of the utility model is uniformly distributed in the whole film layer structure, especially in the middle of the film layer structure, and the stress is distributed about 45 MPa-60 MPa.

Illustratively, as shown in FIG. 1 and FIG. 2, the ratio of the arc radius of the first large curvature arc edge 111 a to the arc radius of the first small curvature arc edge 111 b is 3:6, the ratio of the arc radius of the first small curvature arc edge 111 b to the diameter of the first stress adjustment hole 101 is 6:4, the ratio of the shortest distance of the first large curvature arc edge 111 a to the geometric center of the first stress adjustment hole 101 to the diameter of the first stress adjustment hole 101 is 11.5:4, and the aperture of the first stress adjustment hole 101 is the same as that of the second stress adjustment hole 102. At this time, the maximum tensile stress of the film layer structure is 306.7 MPa, which is less than the maximum tensile stress of the existing metal wire film layer structure. In addition, as can be seen from FIG. 3, the stress of the film layer structure provided by the embodiment of the utility model is uniformly distributed in the whole film layer structure, especially in the middle of the film layer structure, and the stress is distributed at about 50 MPa.

The embodiment of the utility model also provides an array substrate, which comprises at least one film layer structure.

Compared with the prior art, the beneficial effects of the array substrate provided by the embodiment of the utility model are the same as the beneficial effects of the film layer structure provided by the above embodiment, and will not be repeated here.

Wherein one of the at least one film layer structure is a source and drain electrode. Of course, the above film layer structure may be a film layer structure made of a metal material such as a gate electrode, scanning lines, signal lines, or the like, or a film layer structure made of an inorganic material having an elastic modulus close to that of the metal material.

The embodiment of the utility model also provides a display device, which comprises the array substrate.

Compared with the prior art, the beneficial effects of the display device provided by the embodiment of the utility model are the same as those of the array substrate provided by the above embodiment, and will not be repeated here.

The display device provided by the above embodiment can be any product or component with display function such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame or a navigator.

In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner.

The above description is only a specific embodiment of the utility model, but the protection scope of the utility model is not limited to this. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be covered by the protection scope of the utility model. Therefore, the protection scope of the utility model shall be subject to the protection scope of the said claims. 

What is claimed is:
 1. A film layer structure comprising a film layer substrate, the edge of the film layer substrate having a curved edge for adjusting stress distribution of the film layer structure.
 2. The film layer structure according to claim 1, wherein the film layer substrate has a plurality of stress adjustment holes for adjusting stress distribution of the film layer structure; wherein, a plurality of the stress adjusting holes are uniformly distributed on the film layer substrate; or, a plurality of the stress adjusting holes are unevenly distributed on the film layer substrate; or, the density of stress adjustment holes provided in the film layer substrate gradually decreases along the direction from the center to the edge of the film layer substrate; or, the spacing between the two adjacent stress adjustment holes is larger than the diameter of at least one stress adjustment hole in the two adjacent stress adjustment holes.
 3. The film layer structure according to claim 1 or 2, wherein the film layer substrate comprises at least one curved edge unit, and the plurality of stress adjustment holes comprise at least one first stress adjustment hole corresponding to the at least one curved edge unit one by one and at least one second stress adjustment hole corresponding to the at least one curved edge unit one by one; each curved edge unit comprises a first arc edge subunit and a second arc edge subunit which are connected together, wherein the first arc edge subunit is internally provided with a first stress adjusting hole for adjusting the stress distribution of the film layer structure, and the second arc edge subunit is internally provided with a second stress adjusting hole for adjusting the stress distribution of the film layer structure.
 4. The film layer structure according to claim 3, wherein each curved edge unit comprises a first curved edge subunit having at least a first large curvature curved edge and a first small curvature curved edge, and each curved edge unit comprises a second curved edge subunit having at least a second large curvature curved edge and a second small curvature curved edge; the first large curvature arc edge included in the first arc edge subunit in each curved edge unit is connected with the second small curvature arc edge included in the second arc edge subunit, and the first small curvature arc edge included in the first arc edge subunit in each curved edge unit is connected with the second large curvature arc edge included in the second arc edge subunit.
 5. The film layer structure according to claim 4, wherein the first large curvature arc edge included in the first arc edge subunit in one of the two adjacent curved edge units is connected with the second small curvature arc edge included in the second arc edge subunit in the other curved edge unit; wherein a first small curvature arc edge included in a first arc edge subunit in one curved edge unit is connected with a second large curvature arc edge included in a second arc edge subunit in another curved edge unit.
 6. The film layer structure according to claim 4, wherein the curvatures of the first large curvature arc edge and the second large curvature arc edge in each curved edge unit are the same, the curvatures of the first small curvature arc edge and the second small curvature arc edge in each curved edge unit are the same, and the arc radius of the first small curvature arc edge is larger than the diameter of the first stress adjustment hole.
 7. The film layer structure according to claim 6, wherein the ratio of the arc radius of the first large curvature arc edge to the arc radius of the first small curvature arc edge is (1.8-3.6):(4.5-6.5), the ratio of the arc radius of the first small curvature arc edge to the diameter of the first stress adjustment hole is (4.8-6.5):(2.5-4.5), and the ratio of the shortest distance from the first large curvature arc edge to the geometric center of the first stress adjustment hole to the diameter of the first stress adjustment hole is (10-12):(2.5-4.5).
 8. An array substrate comprising at least one film layer structure according to any one of claims 1-7.
 9. The array substrate according to claim 8, wherein one of at least one of the film layer structures is a source and drain electrode.
 10. A display device comprising the array substrate according to claim 8 or
 9. 